Addition question

[drg1]

I'm adding a 10 x24 addition to the gable end of this building, with the gable end 24 ft wide. What would be the best way to tie in the new slab? Should I drill through the bottom girt into the existing slab, and put a 2 ft piece of rebar into the holes to tie the 2 slabs together ? Or just pour new slab against the existing bottom girt and let it float?

 

[LD1]

If you are knocking the wall out and want the slab to be "one" with the existing slab, then I would tie it in.

If the addition is still going to have the wall there to divide the sections and maybe just a man door to pass through, I'd let it float.

 

[drg1]

The plan is to take existing gable side off, and transfer to new gable end. The existing gable end wall girts will remain with a door installed between the new and old. The new will become a work shop area with a door to isolate the two.will put osb on the current gable end gitrs to isolate the 2 portions. Hope this clears it up a little bit

 

[dave1949]

Has the existing slab been stable for you?

I don't think I would worry too much about it if you can duplicate the base preparation that was done for the existing slab, and the existing slab has been stable.

 

[the old grind]

Not knowing your ground saturation/freezing potential, I'd tie in the footing/slab w/rebar as you suggested. (cheap insurance?) :2cents:

 

[drg1]

Current slab has been stable, now where the addition is, fill will be needed. I was planning on using what we call crusher run, and using a vibrator to compact it down. It will take about 6 inches of rock compaction to get it up to the right height

 

[SPIKER]

You may need to "Remove Soil" then add back fill of a compact-able base so there is no "organic matter" under the slab.

Keeping the exterior wall intact my be cheaper and simply add the same exterior material at the NEW gable end. You should look at the time to remove the existing wall materials, how much of it will be damaged in doing so and then compare that additional cost vs just putting in NEW and making a bigger hole where the two come together. This is what we did in a semi commercial farm building years ago.

Drilling & sticking/Epoxy in Rebar is good choice to tie in the two slabs, heavy compaction in the joint area and NEW area WILL NEED TO BE DONE. then keeping moisture away from the joint and slabs will help keep them from freeze/thaw issues and heaving in future.
Mark

 

[drg1]

Thanks for all the replies, keep them coming

 

[LD1]

I would tie the slabs together as mentioned. I think you have a good plan with the crusher run.:thumbsup:

 

[EddieWalker]

Definitely put rebar into the existing slab. Do you have a SDS or SDS Plus rotary hammer? If not, rent or borrow one. They make drilling into concrete easy and fast. Use a good quality epoxy in the holes to hold the rebar in place.

Are you planning on removing the existing gable wall or just adding a room onto it and extending the roofline?

Be sure to dig your footings as deep as the existing footings. With the separate pads, freezing and moisture can create problems for you if you don't go deep enough and go down to a solid footing.

Eddie